Method and apparatus for detachment of fasteners

ABSTRACT

A severing device having a stationary and a movable cutting blade with the edges of each facing each other and the movable blade is actuated by a toggle-like linkage so that the blades come together to shear an element which drops into a chute. The blades are designed to overlap a very small but finite amount upon completion of severing.

0 United States Patent 1 [111 3,748,936

Minasy 1 July 31, 1973 [54] METHOD AND APPARATUS FOR 2,645,144 7/1953 Williams 269/201 X DETACHMENT 0 FASTENERS 3,203,289 8/1965 Beekley 83/167 X 3,181,408 5/1965 Richards, Sr. 83/630 [75] Inventor: Arthur J. Mlnasy, w d ury, N 2,841,196 7/1958 Zazdrzyk 269 228 x [73] Assignee: Knogo Corporation, Westbury, N.Y.

Primary ExaminerAndrew R. Juhasz [22] Filed. Dec. 15, 1971 Assistant E m n r w D. may [21] Appl. No.: 208,142 Attorney-Joseph M. Fitzpatrick, William J. Brunet et al.

[52] U.S. Cl 83/162, 269/201, 269/228, 57 TR 83/167, 83/604, 83/605, 83/630, 83/694 51 161. C1 826d 7/06 A Sevemg havmg stamnary and a "Mable [58] Field of Search 83/162 167 536 cutting blade with the edges 0f each facing each (her and the movable blade is actuated by a toggle-like llllk- 228 age so that the blades come together to shear an element which drops into a chute. The blades are designed [56] References Cited to overlap a very small but finite amount upon comple- UNITED STATES PATENTS severng 265,016 9/1882 Campbellm, 83/630 X 9 Claims, 9 Drawing Figures PATENIED JUL 3 I I975 SHEET 2 [IF 3 METHOD AND APPARATUS FOR DETACHMENT OF FASTENERS This invention relates to the removal of labels from articles of merchandise and more particularly, it concerns a novel severing device for cutting through a thick plastic button element and a shank enclosed thereby to release a label from an article of merchandisc.

The present invention is suited for detachment of labels held to articles of merchandise by label attachment means of the type shown and described in U. S. Patent Application Ser. No. 599,922 filed Dec. 7, 1966, now U.S. Pat. No. 3,628,267 and in U. S. Patent Application Ser. No. 6,004 filed Feb. 7, 1970 now U.S. Pat. no. 3,656,679. In those applications, there is described a label attachment means comprising a tack-like element whose shank pierces an article of merchandise and a label, and a thick button element which fits over the end of the tack shank. The button element is pushed up along the shank so that the merchandise and the label become tightly squeezed together between the head of the tack-like element and the button element. The shank of the tack-like element is secured to the button element at a location therealong removed from the end of the button element which pushes against the label and the article of merchandise. Thus, when the button element and tack shank are severed, the fastening arrangement is released and the label may be removed without harm to the merchandise.

In the aforementioned applications, there is described a tool for severing the button element and the tack shank. The present invention is a new and useful improvement to the removal tool of those applications.

According to the present invention, there are provided a pair of knife-like cutter blades whose cutting edges face each other. The blades are mounted and arranged to move toward and close in on each other for severing a label attachment button element and a tack shank enclosed thereby. Immediately above and adjacent the cutter blades, there is provided a thin platelike cover member. The cover member is formed with an opening through which the label attachment button element can be projectedinto the path of cutter blade movement. The opening is arranged such that the cutter blades close near the center thereof so that both blades do a similar amount of cutting. By using two blades in this manner and causing each blade to cut both the button element and the tack shank, the tack shank is severed in a manner that no burr is formed along one side thereof. In the past, difficulties had been experienced with the laterally projecting burrs which resulted from the severing action of cutter blades on the tack shank. These burrs would snag on and sometimes tear the merchandise when the severed tack was removed after the severing operation. With the dual cutter arrangement of the present invention, both cutter blades close in on the tack shank from opposite sides thereof and their combined cutting action forms a tapered configuration at the end of the severed tack shank. This tapered configuration has a far smaller burr than that which resulted from cutting with a single blade. Further, any burr which is formed is confined to the end of the tapered configuration and lies well within the lateral extent of the tack shank.

In order to ensure that both cutter blades perform a substantially equal amount of cutting so that they both reach the tack shank and cut into it after the button element has been severed, there is provided a thin platelike cover member which lies immediately adjacent the cutter blades along the plane of their path of movement. This cover member is formed with an opening which is located such that it opens between the cutter blades when they are apart and such that the cutter blades close near the center of the opening. The button element to be severed is positioned in this opening in the path of cutter blade movement and is stabilized thereby during the cutting operation.

According to one aspect of the present invention, substantially equal cutting action .by two cutter blades is obtained by operating only one of them. This is achieved by maintaining one of the cutter blades ,stationary on a base and actuating the other blade for back and forth movement along the base relative to the first cutter blade. Further, according to this aspect of the present invention, the cover member is provided with an elongated opening and the stationary cutter blade extends part way across this opening. The remainder of the opening, which is cleared by the movable cutter blade in its opened position, is large enough to accommodate the button element to be severed. Then, as the movable cutter blade closes in on the stationary blade, both blades operate to cut the button element from opposite sides and thereafter severthe tack shank. During the process, the button element moves back along the elongated opening against the stationary cutter blade at approximately half thevelocity of the movable cutter blade.

According to another aspect of the present invention, there are provided novel arrangements for controlling the closure of the cutter blades so that a well defined cut is made with maximum force being applied to the tack shank being severed at the end of the severing operation and yet with minimum damage to the cutter edges themselves. The edgesof the cutter blades of the present invention are bevelled on one side, and oneof the blades is formed with a very small but finite additional bevel on the opposite side. This additional bevel permits a small but positve overlap of the blades when they close in upon each other. In addition, the cutter blade movement is obtained through a toggle linkage which obtains a maximum closing force at the closed position, and at the same time is self-limiting in its closure movement. This self-limiting closure movement provided by the toggle linkage, however, does not detract from the closing force experienced by the button element and tack shank being severed. Thus, a clean sharp cut is obtained without appreciable cutter blade deterioration.

Accordingto a still further aspect of the present invention, there is provided a novelejection chute arrangement which ejects the severed-off portions of the button elements and tack shanks. This novel ejection chute is made of resilient sheet material and is formed to open sufficiently wide to accommodate the entire space between the cutter blades when they are fully opened. The chute extends down from its opening to an outlet near the bottom of the cover member. Thus, any debris of foreign material which may fall into the cover opening when the cutter blades are opened, will'be caught by the chute and guided to the outlet. In-this manner, the cutter blade actuator and guide mechanisms are protected. As the cuttert blades are closed the chute, because of its resilience, will bend and narrow itself in response to the closing action of the blades. However, because the chute is closed by the blade movement, it remains centered with respect to the cutting action and, therefore, remains in a proper position to accept the severed portions of the button element and tack shank.

There has thus been outlined rather broadly the more important features of the invention in order that the detailed description thereof that follows may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional features of the invention that will be described hereinafter and which will form the subject of the claims appended hereto. Those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures for carrying out the several purposes of the invention. It is important, therefore, that the claims be regarded as including such equivalent construction as do not depart from the spirit and scope of the invention.

A specific embodiment of the invention has been chosen for purposes of illustration and description, and is shown in the accompany drawings, forming a part of the specification wherein:

FIG. I is a perspective view showing a label detachment device, in which the present invention is embodled, and a label having an attachment element which is removed by the label detachment device;

FIG. 2 is a perspective view showing the internal construction of the label detachment device of FIG. 1, and showing a portion of thecover thereof in exploded relation to the device;

FIG. 3 is an enlarged section view taken along line 3-3 of FIG. 1 at the initiation of operation of the label detachment device; 4

FIG. 4 is a view similar to FIG. 3, but showing the device at the completion of a severing operation;

FIG. 5 is a view taken along line 5-5 of FIG. 3;

FIG. 6 is an enlarged fragmentary view of a portion of FIG. 3;

FIG. 7 is an enlarged fragmentary view of a portion of FIG. 4;

FIG. 8 is an enlarged side elevational view showing an actuating mechanism in the detachment device of FIG. I at the initiation of operation; and

FIG. 9 is a view similar to FIG. 8, but showing the actuating mechanism at the completion of a severing operation.

The label detachment device of FIG. 1 includes a base 10 upon which is mounted a box-like cover 12. The cover 12 is attached to the base 10 by means of attachment screws 14. The cover 12 is formed with a handle opening 16 at the rear thereof and an actuating handle 18 extends out from this opening. The handle 18 is movable up and down through an are indicated by the arrow A in FIG. 1.

A top opening 20 is formed near the front of the cover 12. This opening is elongated in the longitudinal direction of the cover and, as shown in Fig. 1, there is provided a stationary cutter blade 22 which extends trans-versely across the opening near the forward end thereof. As will be explained more fully hereinafter, when the handle 18 is depressed, a movable cutter blade (not shown) moves forwardly under the cover opening 20 until it meets with the stationary blade 22.

A flat wafer-like label 24 is shown in FIG. 1 to be secured to a piece of fabric 26 by an attachment device including an attachment button 28. The construction and operation of the button 28 is the same as that shown and described in applicants copending U. S. Patent Application Ser. No. 599,922.

In operation of the label detachment device shown in FIG. 1, the piece of fabric 26 (which may be a portion of an article of merchandise) with the label 24 attached thereto by the button 28, is laid on top of the detachment device so that the attachment button 28 enters into the top opening 20. The handle 18 is then depressed and the movable cutter blade squeezes the attachment button 28 between itself and the stationary cutter blade 22; and the two cutter blades cooperate to sever the attachment button 28.

Turning now to FIG. 2, it will be seen that there is provided a rectangularly-shaped slab-like cover mounting block 30 located centrally on the base 10. A stationary blade mounting block 32 is secured to the base 10 immediately in front of the cover mounting block 30. As can be seen, the stationary cutting blade 22 is secured to the stationary blade mounting block 32 by means of a pair of attachment screws 34. A movable cutter blade 36 is positioned in the same plane as the stationary cutter blade 22 and is movable relative to the stationary blade 22 in a direction longitudinally of the label detachment device. The movable blade 36 is secured by means of attachment screws 38 to a movable blade mounting block 40 which slides back and forth on the cover mounting block 30. The lower portion of the movable mounting block 40is provided with a laterally extending flange 42 which is engaged by guide blocks 44 to maintain the movable blade mounting block in a fixed orientation for longitudinal sliding movement on the cover mounting block 30. The guide blocks 44 are secured to the cover mounting block 30 by means of attachment screws 46. A stop pin 48 is mounted in the cover mounting block 30 to limit the rearward movement of the movable mounting block 40.

An actuator support bracket 50 is mounted on the cover mounting block 30 rearwardly of the movable blade mounting block 40. The actuator support bracket includes a bottom flange portion 52 which is secured to the cover mounting block 30 by means of attachment screws 54. The actuator support bracket 50 includes a forwardly positioned tubular guide 56 and a rearwardly positioned pivot support 58, both of which are substantially aligned with the longitudinal axis of the base 10. An actuator rod 60 passes through the tubular guide 56 and is secured to the movable blade mounting block 40. The actuator rod fits closely inside and is guided for longitudinal sliding movement within the tubular guide 56. A connecting link 62 is pivotally connected between the forward end of the actuating handle 18 and the rear of the actuator rod 60. A fixed pivot 64 interconnects the pivot support 58 and a point on the actuator handle 18 displaced a short distance from its forwardend. A stop element 66, which projects from the lower side of the handle 18, serves to engage the actuator support bracket 50 in the vicinity of its pivot support 58 so as to limit the extent of downward movement of the actuator handle 18. It will be appreciated that as the handle 18 is moved downwardly, the portion thereof ahead of the fixed pivot 64 will move upwardly and outwardly toward the front of the device. This forward movement is transmitted via the connecting link 62 to the actuator rod 60 which is guided by the tubular guide 56 for controlled longitudinal movement forwardly of the device. This movement is communicated to the movable blade mounting block 40 which, in turn, forces the movable blade 36 toward the stationary blade 22. The blades may be separated simply by pulling up on the handle 18 which will reverse the action of the actuator mechanism.

It will further be noted that there is provided between and beneath the stationary and movable cutter blades, a guide chute 68 which inclines downwardly to the side of the device. TI-Ie guide chute 68 is fashioned of sheet material bent to a generally U-shaped or channelshaped cross-section. The guide chute 68 is secured to the stationary blade mounting block 32 by means of a fastening screw 70.

Turning now to FIG. 3 wherein the cutter blades 22 and 36 are shown in their opened position, it will be seen that the guide chute 68 has an upper sidewall 72 which extends rearwardly of the forward edge of the movable cutter blade 36, even when that cutter blade is in its rearwardmost position. Thereafter, when the cutter blade 36 moves to its forwardmost position, its mounting block 40 engages the wall 72 of the guide chute 68 and forces it in a forward direction. When the cutter blade 36 is moved rearwardly again, the wall 72 will follow this movement and revert to the position shown in FIG. 3. By making the wall 72 of resilient material and mounting it so that it can bend back and forth with movements of the movable blade mounting block 40, it is possible to ensure that the cover opening 20 will be fully accommodated at all times by theguide chute 68 so that whenever any objects are passed into the opening 20, they will be guided by the chute 68. As can be seen in FIG. 1, the bottom of the chute 68 communicates with an outlet opening 74 in the side of the cover 12 for the discharge of any material which collects in the chute. 4

As can be seen in FIG. 3, when the label 24 is laid on top of the cover 12, the attachment button 28 extends down into the opening 20. The attachment button 28 is held to the label and to the piece of fabric 26 by means of a tacklike fastener element 76. The tack-like fastener element has a shank which passes through the fabric 26 and the label 24 and vdown through the center of the attachment button 28. The lower end of the shank 78 is clinched over and interlocks with the lower end of the attachment button 28. When the cutter blades 22 and 36 come together, as shown in FIG. 4, they sever not only the lower portion of the attachment button 28, but also the shank 78 above where it is clinched over and interlocked with the attachment button. As a result, as shown in FIG. 4, when the severing action is complete, a lower portion 28a of the attachment button 28 along with a lower end 78a of the tack shank 78, is removed and these elements fall into the guide chute 68 and eventually pass out through the opening 74 of the cover 12. With the button and shank thus severed, there is no interlock between them and the label and piece of fabric may both be pulled off the remaining portion of the shank and separated from each other without damage to either.

Turning now to FIG. 5, it will be seen that when the button element 28 is placed into position for a cutting operation, it lies against a cutting edge 80 of the stationary cutter blade 22 while a further cutting edge 82,

on the movable cutter blade 36, is displaced a short distance from the button. When the movable blade 36 closes against the button 28, its cutter edge 82 not only begins to sever the button 28, but it also forces the button against the cutting edge of the stationary cutter blade 22. In this manner, the cutting action is shared equally by the two blades so that they will meet at the tack shank 78 to cooperate in severing it. It is important that the two blades meet at the shank 78 since, as will be described more fully hereinafter, this cooperative cutting of the shank by both blades serves to prevent the occurrence of any burrs on the remaining portion of the shank which might otherwise snag on and damage the fabric 26 to which the label 24 is attached.

FIGS. 6 and 7 show more clearly the action of the stationary and movable cutter blades 22 and 36. As shown in FIG. 6, the two cutter blades are aligned with each other and are in a position for severing the button 28 and the tack shank 78. As the movable blade 36 proceeds in a leftward direction, as viewed in FIGS. 6 and 7, its cutter edge 82 engages the side of the attachment button 28 and begins to cut into the side of the button. At the same time, the forces applied in a leftward direction to the side of the button 28 by the movable cutter blade 36, force the button itself in a leftward direction against the stationary cutter blade 22 so that its cutting edge 80 also cuts into the button 28 from the opposite side thereof. Thus, in spite of the fact that only one of the cutter blades is movable, the cutting action of the two blades is substantially identical since the forces supplied via the movable cutter blade 36 are used not only to cause the blade 36 to cut into the element, but also to drive the button element into the stationary cutter blade 22. In order for this action to occur, the button element 28 must be capable of moving freely in a leftward direction by an amount of approximately equal to one half the total movement of the movable cutter blade 36. Thus, as shown in FIG. 7, it will be seen that the attachment button 28 has 'moved a distance approximately equal to one half its diameter upon the completion of the cutting operation.

It will be seen from FIGS. 6 and 7 that both the stationary and movable cutter blades 22 and 36 have their cutting edges 80 and 82 formed by virtue of a bevelled surface 84 extending upwardly from their respective lower surfaces. The upper surfaces of the two blades remain substantially coplaner in close sliding relationship with the undersurface of the cover 12. A very small but finite secondary bevel 86 is provided on the upper surface of the stationary cutter blade 22 so that its cutting edge 80 is actually positioned a very slight degree downwardly of the cutting edge 82 of the movable cutter blade 36. This configuration of the cutting edges allows the movable cutter blade 36 to ride up slightly on the stationary cutter blade 22, as shown in FIG. 7, upon completion of a cutting operation. This permits the blades to come together fully and even to overlap by a slight amount without damage to the sharp edges of either blade.

FIGS. 8 and 9 illustrate the action of the actuator mechanism which includes the handle 18, the connect of the actuator handle produces maximum movement of the connecting link 62. When, however, the actuator handle 18 is pushed downwardly, as shown in FIG. 9, all of the pivot points between the actuator rod 60 and the connecting link 62, the actuator handle 18 and the fixed pivot 64 are in alignment. In this region of actuator handle movement, the actuator mechanism is incapable of producing any longitudinal movement of the actuator rod 60.

It will be appreciated that as the actuator handle 18 moves from thefposition shown in FIG. 8 to that shown in FIG. 9, a toggle-like action is produced on the cutter blades '22 and 36. Two significant advantages are achieved by this arrangement. Firstly, because of the toggle effect, the maximum closing force is imposed upon the blades at the completion of the severing operation, thereby insuring that the blades will complete their cutting of both the actuator button 28 and the tack shank 78, and a clean, sharp cut will be produced with minimal burring.

Secondly, the toggle-like characteristic of the actuator mechanism automatically prevents the movable blade from substantial overlap of the stationary blade 22. The blades are thus protected from damagewhich might occur if they were allowed to overlap to any great extent. It will be appreciated that the arrangement shown herein provides substantial improvement over other arrangements for preventing blade overlap such as stop elements and the like. This is because stop elements and the like generally become subjected to wear and, therefore, will not, after much usage, maintain the precise end positioning of the cutter blades. Moreover, and even more importantly, when a stop element is used, the force of the actuator mechanism is no longer fully communicated to the cutter blades, but instead is divided btween the cutter blade and the stop element so that a complete severing is not insured.

Having thus described the invention with particular reference to the preferred form thereof, it will be obvious to those skilled in the art to which the invention pertains, after understanding the invention, that various changes and modifications may be made therein without departing from the spirit and scope of the invention, as defined by the claims appended hereto.

What is claimed is:

l. A detachment device for removal of labels held to merchandise by means of a tack-like fastener element whose shank passes through the label and the merchandise and into a thick button element where it is secured, said detachment device comprising a base, a pair of cutter blades mounted above said base with their cutting edges facing each other, a blade actuator mechanism for driving on of the cutter blades toward the other, a thin plate-like cover member secured to the base and covering said cutter blades and actuator mechanism and lying immediately adjacent said cutter blades along the plane of their path of relative movement, said cover member being found with an opening to accomodate a thick button element of a label attachment means to be severed, said opening being located at a position such that said cutter blades meet near the center of said opening.

2. A detachment device according to claim 1 wherein a guide chute is provided below and between said blades to catch objects severed thereby and to direct said objects out from inside said cover.

. together of said blades.

4. A detachment device according to claim 1 wherein each blade is beveled by a major amount in the same direction as the other blade to form cutting edges in substantially the same plane, one of said blades having an additional minor bevel in the opposite direction along its cutting edge to offset the plane of its cutting edge a slight but finite amount with respect to the cutting edge of the other blade to permit a slight overlapping of the blade edges without destruction of the sharpness thereof as the blades are brought together.

5. A detachment device according to claim 1 wherein said cutting edges are formed by a bevel on the edge of said cutter blades, the bevel being in the same direction for each blade so that the resulting cutting edges are formed in substantially the same plane.

6. A detachment device according to claim 1 wherein the plane of the cutting edge of one blade is offset a small but finite amount with respect to the plane of the cutting edge of the other blade to permit a slight overlapping of the blade edges without destruction of the sharpness thereof as the blades are brought together.

7. A detachment device for removal of labels held to merchandise by means of a tack-like fastener element whose shank passes through the label and the merchandise and into a thick button element where it is secured, said detachment device comprising a base, a pair of cutter blades mounted above said base with their cutting edges facing each other, means guiding said blades for relative movement toward and away from each other in the plane defined by their cutting edges, means for actuating blade movement, the last mentioned means comprising a toggle link mechanism mounted on said base and connected to one of said cutter blades said toggle link mechanism beingarranged on said base to be in fully extended condition when said cutter blade edges have come together.

8. A detachment device according to claim 7 wherein said toggle link mechanism comprising a first lever mounted for pivotal movement about a fixed pivot on said base, one end of said lever on one side of said pivot being formed as a handle, a connecting link pivotally connected at one end to the other end of said first lever on the other side of said pivot, the other end 'of said connecting link being pivotally connected to a guide bar to which is connected said moveable blade and means fixed on saidbase for guiding said guide bar for reciprocal movement along a line which extends to said fixed pivot.

9. A detachment device for removal of labels held to merchandise by means of a tack-like fastener element whose shank passes through the label and the merchandise and into a thick button element where it is secured, said detachment device comprising a base, a first cutter blade fixedly mounted on said base to extend thereabove with its cutting edge substantially parallel to the base, a second cutter blade, an actuator mechanism mounted on said base and constructed and arranged to move said second cutter blade back and forth along and above said base so that its cutting edge moves against and away from the cutting edge of the fixed first cutter blade, the cutting edges of the two blades being traversed by the cutting edge of said fixed cutter blade, the remainder of said opening being sufficiently large to accomodate a button element and located in a position to be cleared by the second cutter blade when moved away from the cutting edge of the first cutter blade.

l I t 4' I 

1. A detachment device for removal of labels held to merchandise by means of a tack-like fastener element whose shank passes through the label and the merchandise and into a thick button element where it is secured, said detachment device comprising a base, a pair of cutter blades mounted above said base with their cutting edges facing each other, a blade actuator mechanism for driving on of the cutter blades toward the other, a thin platelike cover member secured to the base and covering said cutter blades and actuator mechanism and lying immediately adjacent said cutter blades along the plane of their path of relative movement, said cover member being found with an opening to accomodate a thick button element of a label attachment means to be severed, said opening being located at a position such that said cutter blades meet near the center of said opening.
 2. A detachment device according to claim 1 wherein a guide chute is provided below and between said blades to catch objects severed thereby and to direct said objects out from inside said cover.
 3. A detachment device according to claim 2 wherein said guide chute has resiliently moveable walls which widen to accomodate the entire cover opening while said cutter blades are farthest apart, said guide chute walls being deflectable to be closed in by the coming together of said blades.
 4. A detachment device according to claim 1 wherein each blade is beveled by a major amount in the same direction as the other blade to form cutting edges in substantially the same plane, one of said blades having an additional minor bevel in the opposite direction along its cutting edge to offset the plane of its cutting edge a slight but finite amount with respect to the cutting edge of the other blade to permit a slight overlapping of the blade edges without destruction of the sharpness thereof as the blades are brought together.
 5. A detachment device according to claim 1 wherein said cutting edges are formed by a bevel on the edge of said cutter blades, the bevel being in the same direction for each blade so that the resulting cutting edges are formed in substantially the same plane.
 6. A detachment device according to claim 1 wherein the plane of the cutting edge of one blade is offset a small but finite amount with respect to the plane of the cutting edge of the other blade to permit a slight overlapping of the blade edges without destruction of the sharpness thereof as the blades are brought together.
 7. A detachment device for removal of labels held to merchandise by means of a tack-like fastener element whose shank passes through the label and the merchandise and into a thick button element where it is secured, said detachment device comprising a base, a pair of cutter blades mounted above said base with their cutting edges facing each other, means guiding said blades for relative movement toward and away from each other in the plane defined by their cutting edges, means for actuating blade movement, the last mentioned means comprising a toggle link mechanism mounted on said base and connected to one of said cutter blades said toggle link mechanism being arranged on said base to be in fully extended condition when said cutter blade edges have come together.
 8. A detachment device according to claim 7 wherein said toggle link mechanism comprising a first lever mounted for pivotal movement about a fixed pivot on said base, one end of said lever on one side of said pivot being formed as a handle, a connecting link pivotally connected at one end to the other end of said first lever on the other side of said pivot, the other end of said connecting link being pivotally connected to a guide bar to which is connected said moveable blade and means fixed on said base for guiding said guide bar for reciprocal movement along a line which extends to said fixed pivot.
 9. A detachment device for removal of labels held to merchandise by means of a tack-like fastener element whose shank passes through the label and the merchandise and into a thick button element where it is secured, said detachment device comprising a base, a first cutter blade fixedly mounted on said base to extend thereabove with its cutting edge substantially parallel to the base, a second cutter blade, an actuator mechanism mounted on said base and constructed and arranged to move said second cutter blade back and forth along and above said base so that its cutting edge moves against and away from the cutting edge of the fixed first cutter blade, the cutting edges of the two blades being parallel to each other and lying in a common plane, a thin plate-like cover member also fixedly mounted on said base and covering said cutter blades and lying immediately adjacent said cutter blades along the plane of their path of relative movement, said cover member being formed with an elongated opening, a portion of said opening extending over said fixed cutter blade and traversed by the cutting edge of said fixed cutter blade, the remainder of said opening being sufficiently large to accomodate a button element and located in a position to be cleared by the second cutter blade when moved away from the cutting edge of the first cutter blade. 